A lubrication system is disclosed in U.S. Pat. No. 4,785,913 for cyclically positively dispensing accurate liquid lubricant injections through a pressure resisting check valve into a pressurized oil filled delivery tube passage leading through a second pressure resisting check valve to a nozzle directed toward a lubrication target, and continuously supplying air under regulated pressure at the outlet of the second check valve to atomize, entrain and scour each injection of lubricant from surfaces at the check valve and nozzle, in order to deliver an accurate quantity of atomized lubricant mist during a substantial period of time following each positive injection of lubricant.
The present invention relates to a lubrication monitoring system which may have application to said lubricating system as a specific example, or other lubricating systems, where it is desired to detect pressure/flow defects. Potential malfunctions for which monitoring may be desired include, without limitation, the following:
1) a break in delivery line, or slight leak such as may occur overnight; PA1 2) a blocked line arising from PA1 3) check valve malfunction; PA1 4) tampering with air pressure regulator; PA1 5) injector fails to fire; PA1 6) electrical components fail; PA1 7) oil reservoir empty. PA1 1) Catalyst beads and/or hot wire anemometry which detect temperature/resistance changes in the bead or wire (inserted into fluid channel) in response to thermodynamic changes of the fluid/wire system due to its flow; PA1 2) optical methods including laser-dopler velocimetry; PA1 3) positive displacement proximity detectors which involve movement of metallic objects within the fluid and which either activate a switch contact or sense through proximity detectors (inductive/capacitive); PA1 4) traditional means such as the venturi configuration and pitot tube which rely upon space-differential pressure measurements.
a) bent tube, PA2 b) dirt or sediment, PA2 c) metal chips, PA2 d) oil inclusions, PA2 e) crushed nozzle, PA2 a) air failure PA2 b) piston breaks
Commercial applications include industrial injection lubrication systems; high speed spindle lubrication systems; chain lubrication; tenter clip lubrication; drilling and milling lubrication operations; air pneumatic processing dispensing of high viscosity oils, silicones and sludge compounds; dispensing of low viscosity substances, or any fluid system characterized by transient flow processes.
Prior state of the art includes various techniques for detecting fluid flow including:
Limitations of prior systems to detect pressure/flow defects for the complete range of potential malfunctions without undue complexity and expense or need for readjustment to correspond with user adjustment of injection stroke or frequency has led to the need for and development of the present, relatively simple and versatile solution applicable to virtually all commercial systems employing cyclical positive injection.